Abstract

In this paper, we introduce a novel non-parametric thresholding method that we term Mutual-Information
Thresholding. In our approach, we choose the two detection thresholds for two input signals such that the
mutual information between the thresholded signals is maximised. Two efficient algorithms implementing our
idea are presented: one using dynamic programming to fully explore the quantised search space and the other
method using the Simplex algorithm to perform gradient ascent to significantly speed up the search, under the
assumption of surface convexity. We demonstrate the effectiveness of our approach in foreground detection
(using multi-modal data) and as a component in a person detection system.